[NM020AAZ], Technical Note, Thomas Alva Edison, July 1st, 1886


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[NM020AAZ], Technical Note, Thomas Alva Edison, July 1st, 1886

Editor's Notes

(Drawing with text label "D phosphoric anhydride or other absorber of water") "Dyer-- Take out patent and assign to Lamp Co for following. They are a series of Soak patents hence broad claims. A&B are tubes containing an abosrbant of Chlorine Bromine or Iodine Vapors such as Quicksilver & such metals as ones that combine with Chlorine at ordinary temperatures or slight increase of temperatures above the ordinary such as Copper Zinc Iron, alkali metal C is a tube containing solid Iodine or a salt of Iodine which gradually gives off vapors of Iodine, or a chloride which gives off free chlorine gradually or a chloride that gives off it heat slowly by a gentle heat such as sesquichloride of chromium, or an inert porous material like charcoal etc saturated with chlorine gas Bromine & salts acts the same as chlorine-- The object of this trap is to prevent mercury vapors from passing from the drop tube to the lamp. Iodine Chlorine or Bromine all attache Mercury at ordinary temperatures forming an Iodide Bromide or Chloride. Consequently no mercury reaches the Lamp-- The object of tubes A & B is on the one hand to prevent these gases or vapors from going into the fall tube where they would combine with the mercury & dirty the tube so ti wouldn't work & on the other hand prevent the gas used from entering the Lamp. The mtals in tubes are attacked by the gases & form solid Chlorides Bromides or Iodides. There are absorbant substances that will absorb the gases in the pores of the same that could be used in A & B such as oxides magnesia, charcoal & other inert substances that absorb gases; a compound could be used with which the gas or vapor combine, such as quicklime in the case of chlorine. The object of getting the Mercury out of the globe is to diminish the blue and lengthen the life of the filiment I spose you can make a claim for a chemical substance between the Lamp and the Mercury pump which will combine with the vapors of mercury to make a solid. There are other chemical substances which when mercury passes through or over them combines besides the ones names such as heated sulphur, vapors of nitric acid in fact any chemical could off hand suggest a dozen things in A B & C that would accomplish the object hence I want to get very broad claims--"



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Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University
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